What cardiac glycoside is found in lily of the valley?

What cardiac glycoside is found in lily of the valley? Convallatoxin.

Convallatoxin is a naturally occurring cardiac glycoside found in lily of the valley, Convallaria majalis. The compound is named for the plant's scientific genus, Convallaria, and is part of the broader cardenolide group of digitalis-like substances.

Its pharmacological target is the sodium–potassium pump, or Na⁺/K⁺-ATPase, in cell membranes. In cardiac tissue, inhibition of this pump changes sodium and calcium handling, increasing the force of contraction while also affecting electrical conduction and heart rhythm. That same potency makes excessive exposure dangerous.

Lily of the valley has a long medicinal history, with traditional European herbalists using it for heart-related complaints. It was sometimes treated as an alternative to foxglove, the source of digitalis compounds. Modern readers may also recognize the plant from the television series Breaking Bad, but the real toxicology is broader than that fictional plot: ingestion can produce nausea, vomiting, dizziness, visual disturbances, arrhythmias, seizures, coma, or cardiac arrest.

Convallatoxin is not the same molecule as digoxin, although both are cardiac glycosides with related effects.